Touch panel

#1. Field of the Invention

#The present invention relates to touch panels for operating electronic devices.

#2. Background Art

#FIG. 1 is a plan view of a touch panel in a preferred embodiment of the present invention.

#FIG. 2 is a sectional view of the touch panel in FIG. 1, taken along line 2-2.

#FIG. 3 is a sectional view of the touch panel in another preferred embodiment of the present invention.

#A preferred embodiment of the present invention is described below with reference to FIGS. 1 to 3.

#FIG. 1 is a plan view of a touch panel in the preferred embodiment of the present invention. FIG. 2 is a sectional view of the touch panel shown in FIG. 1 taken along line 2-2. In FIGS. 1 and 2, flexible wave plate 21 is a quarter-wave plate given birefringence by stretching a film typically of polycarbonate resin or cyclo-olefin polymer. Light-transmissive first substrate 27 (herein after referred to as ‘substrate 27’) is film-shaped. Substrate 27 is made of an optically-isotropic material, typically polycarbonate resin or polyethersulfone resin. Wave plate 21 and substrate 27 are laminated to configure substrate body 30 which is a laminated substrate. Light-transmissive second substrate 22 (herein after referred to as ‘substrate 22’) is made of an optically-isotropic material, typically polycarbonate resin, polyethersulfone resin, or glass. Substrate 22 is a lower substrate. Light-transmissive first conductive layer 23 (herein after referred to as ‘layer 23’), made typically of indium tin oxide or tin oxide, is formed at a lower face of wave plate 21. Layer 23 is an upper conductive layer formed at a face, which is a side of substrate 22, of substrate body 30, also. Light-transmissive second conductive layer 24 (herein after referred to as ‘layer 24’), made typically of indium tin oxide or tin oxide, is also formed on a top face of substrate 22. Layer 24 is a lower conductive layer, and the top face of substrate 22 is a face facing to layer 23. Layer 23 and layer 24 are formed typically using sputtering.

#A plurality of dot spacers (not illustrated) are formed, using insulating resin typically epoxy resin or silicone resin, at predetermined intervals on a top face of layer 24. The top face of layer 24 is a face facing to the layer 23. A pair of upper electrodes (not illustrated), made typically of silver or carbon, are formed on both ends of layer 23. A pair of lower electrodes (not illustrated), made typically of silver or carbon, are formed on both ends of layer 24 in a direction perpendicular to the upper electrodes.